Photonic frequency converting transceiver and related methods

Abstract

A photonic frequency converting transceiver may include a laser, and a downconverter receiver branch including a first optical modulator optically coupled to the laser and configured to modulate laser light based upon an RF input signal and a first optical bandpass filter. An upconverter transmitter branch may include a second optical modulator optically coupled to the laser and configured to modulate laser light based upon an intermediate frequency input signal, and a second optical bandpass filter. A shared local oscillator branch may include a third optical modulator optically coupled to the laser and configured to modulate laser light based upon a local oscillator signal, and a third optical bandpass filter. The transceiver may further include photodetectors optically coupled to the optical bandpass filters to generate a downconverted intermediate frequency output signal and an upconverted RF output signal.

That which is claimed is: 
     
       1. A photonic frequency converting transceiver comprising:
 a laser; 
 a downconverter receiver branch comprising a first optical modulator optically coupled to said laser and configured to modulate laser light based upon a radio frequency (RF) input signal, and a first optical bandpass filter optically coupled to said first optical modulator; 
 an upconverter transmitter branch comprising a second optical modulator optically coupled to said laser and configured to modulate laser light based upon an intermediate frequency input signal, and a second optical bandpass filter optically coupled to said second optical modulator; 
 a shared local oscillator branch comprising a third optical modulator optically coupled to said laser and configured to modulate laser light based upon a local oscillator signal, and a third optical bandpass filter optically coupled to said third optical modulator; 
 a first photodetector optically coupled to said first and third optical bandpass filters and configured to generate a downconverted intermediate RF output signal; and 
 a second photodetector optically coupled to said second and third optical bandpass filters and configured to generate an upconverted frequency output signal. 
 
     
     
       2. The photonic frequency converting transceiver of  claim 1 , wherein said first and second optical modulators comprise Mach-Zehnder modulators. 
     
     
       3. The photonic frequency converting transceiver of  claim 1 , wherein each of said first, second, and third bandpass filters comprises a fiber Bragg grating. 
     
     
       4. The photonic frequency converting transceiver of  claim 3 , further comprising a respective polarization maintaining circulator coupled to each of said first, second, and third FBGs. 
     
     
       5. The photonic frequency converting transceiver of  claim 1 , further comprising a respective optical waveguide coupled between each of said first, second, and third bandpass filters and said first and second photodetectors. 
     
     
       6. The photonic frequency converting transceiver of  claim 1 , wherein said first photodetector comprises a balanced photodetector. 
     
     
       7. The photonic frequency converting transceiver of  claim 1 , wherein said laser comprises a continuous wave laser. 
     
     
       8. The photonic frequency converting transceiver of  claim 1 , further comprising an optical amplifier coupled between said laser and said first, second, and third optical modulators. 
     
     
       9. The photonic frequency converting transceiver of  claim 1 , further comprising a common housing; and wherein said downconverter receiver branch, said upconverter transmitter branch, said shared local oscillator branch, and said first and second photodetectors are carried by said common housing. 
     
     
       10. The photonic frequency converting transceiver of  claim 1 , further comprising a photonic chip substrate; and wherein said downconverter receiver branch, said upconverter transmitter branch, said shared local oscillator branch, and said first and second photodetectors are on said photonic chip substrate. 
     
     
       11. A communication system comprising:
 at least one radio frequency (RF) antenna; 
 electronic RF circuitry; and 
 a photonic frequency converting transceiver coupled to said at least one antenna and said electronic RF circuitry and comprising
 a laser, 
 a downconverter receiver branch comprising a first optical modulator optically coupled to said laser and configured to modulate laser light based upon an RF input signal from said at least one antenna, and a first optical bandpass filter optically coupled to said first optical modulator, 
 an upconverter transmitter branch comprising a second optical modulator optically coupled to said laser and configured to modulate laser light based upon an intermediate frequency input signal from said electronic RF circuitry, and a second optical bandpass filter optically coupled to said second optical modulator, 
 a shared local oscillator branch comprising a third optical modulator optically coupled to said laser and configured to modulate laser light based upon a local oscillator signal, and a third optical bandpass filter optically coupled to said third optical modulator, 
 a first photodetector optically coupled to said first and third optical bandpass filters and configured to generate a downconverted intermediate frequency output signal to said electronic RF circuitry, and 
 a second photodetector optically coupled to said second and third optical bandpass filters and configured to generate an upconverted RF output signal to said at least one antenna. 
 
 
     
     
       12. The communication system of  claim 11  wherein said first and second optical modulators comprise Mach-Zehnder modulators. 
     
     
       13. The communication system of  claim 11  wherein each of said first, second, and third bandpass filters comprises a fiber Bragg grating. 
     
     
       14. The communication system of  claim 11  wherein said photonic frequency converting transceiver further comprises a respective optical waveguide connected between each of said first, second, and third bandpass filters and said first and second photodetectors. 
     
     
       15. The communication system of  claim 11  wherein said first photodetector comprises a balanced photodetector. 
     
     
       16. The communication system of  claim 11  wherein said laser comprises a continuous wave laser. 
     
     
       17. A photonic frequency conversion method comprising:
 modulating light from a laser based upon a radio frequency (RF) input signal using a first optical modulator, and filtering the laser light modulated based upon the RF input signal with a first optical bandpass filter; 
 modulating light from the laser based upon an intermediate RF input signal using a second optical modulator, and filtering the light modulated based upon the intermediate frequency input with a second optical bandpass filter; 
 modulating light from the laser based upon a shared local oscillator signal using a third optical modulator, and filtering the light modulated based upon the shared local oscillator signal with a third optical bandpass filter; 
 generating a downconverted intermediate frequency output signal using a first photodetector optically coupled to the first and third optical bandpass filters; and 
 generating an upconverted RF output signal using a second photodetector optically coupled to the second and third optical bandpass filters. 
 
     
     
       18. The method of  claim 17  wherein the first and second optical modulators comprise Mach-Zehnder modulators. 
     
     
       19. The method of  claim 17  wherein each of the first, second, and third bandpass filters comprises a fiber Bragg grating. 
     
     
       20. The method of  claim 17  wherein the first photodetector comprises a balanced photodetector. 
     
     
       21. The method of  claim 17  wherein the laser comprises a continuous wave laser.